Compact lift for van

ABSTRACT

An electrically-operated lift platform is provided for insulation at the side or rear door of a van-type passenger/cargo automobile body. The platform is long enough to accommodate a wheel chair. The platform sides are connected to two linkage mechanisms, secured to the body inside the van at the top and sides of the door opening. The lift, in operation, moves between a position flat on the ground outside the door to a position level with the van floor, keeping horizontal during travel between these positions. The lift also can be moved from the floor position to a storage position in which the lift platform is vertical and entirely within the van, so that the van doors can be closed, when the lift is entirely concealed from outside view. 
     In a first embodiment the lift is operated electrically, and in a second, hydraulically.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of the copending application,now abandoned, by the same applicant, Ser. No. 322,732, filed Jan. 11,1973, for a compact and concealable lift for van.

BACKGROUND OF THE INVENTION

This invention relates to lifts installed in automobiles andparticularly to lifts designed for installation at the side or reardoors of automobile van bodies, and intended primarily to lift wheelchairs.

Lifting tailgates are commonly used in truck bodies to lift heavy loadsfrom the level of the ground to that of the truck bed. These lifts arenot directly adaptable, however, to the purposes of this invention.

SUMMARY OF THE INVENTION

One object of this invention is to provide means for a person, confinedto a wheel chair, to enter and leave the body of an automobile van byhis own, unaided effort.

Another object is to provide a power-operated lift for installation inthe door opening of an automobile van body, the lift being entirelyconcealed within the van when not in use and with the door closed.

Another object is to provide a lift for lifting, vertically, a weightfrom ground level to floor level of an autombile, the lift including itsplatform being entirely concealed within the automobile body when not inuse.

This invention provides a platform, large enough to carry a wheel chair,secured to two linkages. The linkages are installed inside the side orrear door opening of a van-type automobile body. The points of fasteningof the linkages to the body structure are entirely within the van and donot involve cutting or securing to the outer body surface. When thedoors are closed the lift structure is entirely concealed.

The lift is operated by a small, 12-volt direct-current gear motor,connected to the automobile battery.

The lift platform, in its lowest position, rests on the ground outsidethe van door, so that a wheel chair can be wheeled onto the platform andpositioned parallel to the van body wall. A cord attached to a switch isthen pulled by the wheel chair occupant, starting the lift motor. Whenthe lift platform reaches the van floor level the cord is released, thelift motor stops, and the wheel chair occupant wheels himself onto thevan floor. He then again pulls the cord and the lift platform rotates toa vertical position, while the lifting linkages, one at each side of thedoor opening, nest themselves within the van. The wheel chair occupantthen releases the cord and, both the platform and linkage mechanismsbeing entirely inside the van, he can close the van door.

When the wheel chair occupant desires to leave the van, he wheelshimself along the van floor to the doorway and reverses the describedoperation.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an outside view of the open side door of an automobile van inwhich the lift is installed.

FIG. 2 is a view of one of the stops secured to the van step riser inthe first embodiment.

FIG. 3 is a side view of the stop.

FIG. 4 is a view of the first embodiment from the inside of the van ofthe right side door opening.

FIG. 5 is an end view of the motor, switch and spring shock absorber ofthe first embodiment.

FIG. 6 is an elevation view looking forward, from within the right sidedoor opening, of the first embodiment linkage with the platform down.

FIG. 7 depicts, in the first embodiment, an extension secured to thelower pivot arm.

FIG. 8 depicts the swing arm in the first embodiment.

FIG. 9 depicts the cable-clamping piece in the first embodiment.

FIG. 10 is an enlarged view, in the first embodiment, of the minorlinkage, the lift being in its uppermost position.

FIG. 11 illustrates, in the first embodiment, the attitude of thelinkage at the point in its downward travel at which the minor linkageassumes its folded position.

FIG. 12 illustrates, in the first embodiment, the folded attitude of theminor linkage.

FIG. 13 is a view from within the right side door opening, lookingforward, of the second embodiment linkage, sectioned on the line 13 --13 of FIG. 14, the platform being down.

FIG. 14 is a cutaway view from outside the van of the linkage shown inFIG. 13.

FIG. 15 is a partly sectioned view from within the right side dooropening, looking forward, of the linkage shown in FIGS. 13 and 14 butwith the linkage folded and the platform up in the stowed position.

FIG. 16 schematically illustrates the electro-hydraulic power system ofthe second embodiment for actuating the hydraulic cylinders.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a van having a side door is shown. The dooropening, viewed from outside the van, as a clear opening, 11, in aselected van, 47 inches high and 491/2 inches wide. The installed liftis shown with its platform in its lowest position, resting near theground outside the van. The visible parts of the lift include twolinkages, 12 and 13, each being secured to the inside side wall of thevan above the door. Each linkage also has a second point of connectionto the body of the van, one of the links of each linkage being pivotallysecured to the door jamb, indicated at points 14 and 16. The edge of thelift platform is shown at 17, resting on the ground outside the van.

The first embodiment, depicted in FIGS. 1 to 12, is described asfollows.

Two stops, 18 and 19, are fastened to the riser 21 of the van step. Eachstop is made of angle iron, with one side cut away at the top for ashort distance, as is more clearly shown in FIGS. 2 and 3. The functionof these stops is to aid the linkages, at the top of stroke, in foldingthe lift platform to a vertical position.

FIG. 4 depicts the lift mechanism as seen from inside the van, with thelift platform at its bottom position, on the ground outside the van. Thelinkages 12 and 13 are hinged at 23 and 22 to a steel plate 24 which ispermanently fastened to the van wall, above the door opening. The plate24 is extended at the left, toward the front of the van, and supportsseveral pulleys. One pulley, 26 has the function of changing directionof a steel cable, 27, secured to the linkage 12 and to the side of theplatform 17. Another pulley, 28, carries another steel cable, 29,similarly connected to the front linkage 13 and the other side ofplatform 17. Both cables, 27 and 29, pass over a double-sheave pulley,31, and are secured by a cable clamp 32 to a single cable 33.

A reversible electric gear motor 34 is connected to a reel 36, on whichthe cable 33 is wound. The motor 34 is reversed by a switch mechanism,37, FIGS. 4 and 5, having a spring-loaded operating lever 38. In thehorizontal, middle position of this lever the motor is not activated.When one end of the lever is pulled upward the motor runs forward andwinds the cable 33 on its reel 36. When the other end of the lever ispulled upward the motor runs backward and unwinds the cable. The cords,39 and 41, are secured to the two ends of lever 38 for easy operation ofthe switch from either inside or outside the van.

The motor is based on a hinged plate, 42, which is held down by a spring43 secured to the floor of the van. If extraordinary stress is appliedby cable 33, the motor on its hinged base lifts up against the spring;thus the spring serves as a shock absorber at the top of the liftingmotion of the mechanism.

FIG. 6 generally illustrates the forward linkage, including the platform17 resting near the ground 44 outside the van and at almost the furthestdown position. The major links of the linkage include a suspension arm46 pivoted at 47 to the bar 24 on the inside wall of the van above thedoor opening delimited by the lines 48 and 49. The suspension arm 46 ispivoted to an upper pivot arm 51 and to a lower pivot arm 52 which areof equal length, and which are pivoted at 53 and 54 to a verticalsupport arm 56. The latter is connected near its bottom end, at 57, by ahinge rod to the similar vertical support arm of the rear linkage.Forward and rear linkages are mirror images of each other.

The platform 17 is hinged on the hinge rod and, in its lowest hingedposition relative to the vertical support arm 56, rests on heavy ironangle stops welded to the bottom ends of the front and rear verticalsupport arms. One such stop is indicated at 58.

One additional link, 59, termed the guide arm, completes the majorlinkage. This link 59 is pivoted at one end, 61, to the link 52 and atthe other end, 62, to a selected point in the face of the forward doorjamb 63. This point of fastening to the van structure is, when thesuspension arm 46 is vertical, at a selected distance, a, above thepivot 64 and a selected distance horizontally, b, from the pivot point47. The two points 47 and 62 are the only points of attachment of thislift linkage to the van structure.

The links 46, 51, 52, and 56 constitute a pantograph with equal opposedsides, so that links 46 and 56, throughout movements, are alwaysparallel. The distance 64-71 equals the distance 53-54, and the distance71-53 equals the distance 64-54.

Minor links of the linkage at 66 serve to connect the linkage to a cablefor raising and lowering the linkage and platform. This cable, generallyindicated by the line 29, runs from a pulley 28 down to a slidingdirection changer 67 near pivot 53, then down to the minor linkage 66,to which the cable is securely clamped. From there the same cablecontinues down to be secured at a point 68 on the side edge of theplatform 17.

One function of the minor linkage 66 is, on the up cycle of the liftand, at a selected point in the upward movement, to raise the platform17 on its hinge rod to a nearly vertical attitude.

The minor linkage consists of three parts, illustrated in FIGS. 7, 8 and9. In FIG. 7 an extension 72 is shown welded to the edge of the end oflink 52, near pivot hole 54. In FIG. 8 a link 73 is shown having twopivot holes, 74 and 76. In FIG. 9 a cable-clamping piece 77 is shown.This piece is provided with three holes. In one a cable guide 78 issecured by a bolt. In another a cable clamp 79 is secured, and a thirdhole 81 is provided through which the cable 29 is passed.

When the platform is in its uppermost position the four major links 46,51, 52 and 56 are folded together and the minor linkage elements areextended. FIG. 10 shows the relative extended positions of major link 52with its welded extension 72, minor link 73 and cable-clamping piece 77,with the lift at the top position. The other major links are omitted forclarity, as they would be nested with link 52.

As the lift is lowered the pantograph link 52 moves out to an angle withthe suspension arm 46 and the swing arm 73 rotates slowly clockwise asthe platform is lowered. Finally, at a position of the platform a shortdistance above the floor of the van, the nut 78 strikes the extension72. The attitude at this point of the major linkage is shown in FIG. 11and the folded position of the minor linkage, indicated at 66, isenlarged to FIG. 12.

In the operation of the lift, starting with it in its uppermost, storedposition and with the van doors open, the motor switch is operated toits reversing position, and the cable 33 unwinds. This cable, attachedto the two cables 27 and 29, thereupon allows the minor linkages of themechanism to fall by gravity. This illustrated in FIGS. 10 and 12, thelink 73 rotating on its pivot 74 from the position in FIG. 10 to thatshown in FIG. 12, while the major linkage opens from its nested positionto that shown in FIG. 11. Meanwhile the platform falls from a verticalposition rotating on its hinge rod pivoted at the bottom ends of the twovertical supports, one being illustrated at 56, FIG. 6.

As the platform starts to fall, the hinge edge of the platform, whichextends to the rear for a short distance beyond the hinge rod liesagainst the stops 18 and 19, FIG. 1, presses against these stops andtends to push the platform out and away from its vertical position.

If it is desired to stop the platform at the level of the van floor, themotor operation is stopped when the platform reaches that point. If itis desired to have the platform rest on the ground outside the van, themotor is stopped after the platform has reached the ground.

In retracting the lift from its bottom position, the motor switch isoperated to the forward position and its reel winds up cable 33.Initially, the major linkage is in the position shown in FIG. 6 and theminor linkage as shown in FIG. 12. The cables 27 and 29, as indicated inFIG. 6 for the forward linkage, showing cable 29, now assume stress andlift the mechanism, including front and rear linkages. When the platformreaches the level of the van floor the motor is stopped. The minorlinkages are still in the positions illustrated by FIG. 12 and theweight of the platform is carried by the stops 58, FIG. 6.

To store the lift in its uppermost position the motor is again startedforward and the two linkages and the platform rise. When the platformhas risen an inch or so above the van floor the minor linkages begin tounfold from the position of FIG. 12 to that of FIG. 10, tightening thecables to the platform so that they assume the platform weight and beginrotating the platform on its hinge rod. The rotation of the minorlinkages to the position shown in FIG. 10, and the turning of theplatform to a vertical position, are completed before or just as themechanism reaches its top position.

In this action of the platform, the final movement to a verticalposition is aided by the stops 18 and 19, FIG. 1. These stops are sopositioned that the hinge edge of the platform strikes the stops attheir cutout upper ends and thus prevents the lower edge of the platformfrom moving in further than it should.

In the progress of the lift operation in moving from the "down" positionto the uppermost position, when the entire mechanism including theplatform is inside the inner wall surface of the van, the pivot point54, FIG. 6, rises vertically, then near the top moves inward in a curve.To accomplish this, the relative lengths of the several links must be inselected proportions, particularly the lengths of the four links a, d,e, and f. One example of link proportionality which has been determinedto produce such action is, referring to FIGS. 6 and 10:

    ______________________________________                                        Link              Proportional                                                Designation       Number                                                      ______________________________________                                        a                 1                                                           b                 5.65                                                        c                 11.3                                                        d                 10                                                          e                 4.3                                                         f                 2.67                                                        g                 2.33                                                        h                 1.75                                                        ______________________________________                                    

The second embodiment is shown in FIGS. 13 to 16. It differs from thefirst embodiment in being operated electro-hydraulically instead ofelectrically, in eliminating the cables used to hoist the platform inthe first embodiment, in eliminating the minor linkage, and in themechanism used to change the platform attitude between the horizontaland vertical positions. The links 46, 52 and 59 of the first embodimentare retained substantially in their above-described dimensions and intheir attachments to the van. The link 51 and the minor links 72, 73 and77 are omitted. For link 56 there is substituted a new link, 101,extending from the pivot 54 to the platform 17.

Referring to FIGS. 13, 14 and 15, link 101 is a plate pivoted at 54 tolink 52 and pivoted at 102 to a small plate 103. The latter is securedto the edge of platform 17. The plate 101 is provided with a weldedangle piece 104.

A hydraulic double-acting cylinder 106 is pivoted by a pin 107 to link46 at the point of attachment 22, FIG. 4, to the van above the door.Alternatively, the cylinder pin 107 may be attached to the link 46 or tothe van near, but not precisely at, the pivot location 22.

The piston rod 108 of cylinder 106 is rigidly secured, for example by ashoulder and nut, to the angle piece 104. The latter is thick enough andclose fitting enough that side play of rod 108 relative to link, 101 iseliminated. Thus, when the piston rod 108 is pulled into cylinder 106,the link 101 acts as a rigid extension of rod 108 and remains alignedtherewith.

A rod 109 is provided with a right-angled extension 111 at one end. Thisextension 111 has a hole slightly larger than the rod 108, which passesthrough the hole and is a loose fit therein. The other end of rod 109 issecured to the small plate 103 by a pivot pin 112. A spring 113surrounds piston rod 108 above the right-angled extension 111, and aloose washer 114 above the spring 113 is a sliding fit on rod 108.

The function of rod 109, spring 113, and the pivot pin at point 112 onsmall plate 103 is, when the platform and linkage are raised to theuppermost nested position, to move the platform to a vertical positionin a manner to be explained later.

The cylinder 106 is actuated, as indicated in FIG. 16, by a hydraulicpump 116 connected for energization by an electric motor 117. Thehydraulic fluid is controlled by an electric solenoid valve assembly118. This valve assembly 118 is controlled by two spring-loaded cords,119 and 121. When cord 119 is pulled, it starts the motor 117 andapplies high pressure hydraulic fluid to one of the two pipes 122running to the hydraulic cylinders 106 and 106A. When the other cord ispulled, it starts the motor and applies the high pressure hydraulicfluid to the other of the two pipes 122. Thus one cord causes operationof both hydraulic cylinders in one direction and the other cord causesoperation in the other direction. Such hydraulic actuation is wellknown.

The second embodiment linkage illustrated in FIGS. 13, 14 and 15 isduplicated in mirror image at the other side of the van door opening 11,FIG. 1, and operation of the van lift is generally as described for thefirst embodiment except in the manner of rotating the platform 17between its horizontal and vertical attitudes and in the substitution ofelectro-hydraulic actuation of the lift for electrical actuation.

With the platform 17 in the "down" position, FIGS. 13 and 14, one of thecords, 119, FIG. 16, is pulled. This actuates both cylinders 106 and106A, pulling both piston rods upward and raising the platform while notsubstantially affecting its horizontal posture. When the platform islevel with the floor, the cord is released and the platform stays aspositioned. To raise the platform to its uppermost position, the samecord, 119, is again pulled and the platform rises. When the washer 114hits the lower end of the hydraulic cylinder 106 it exerts pressure,through the buffer spring 113, on the right-angled extension 111 of therod 109. This rod in turn presses, through the small plate 103, on thatpart of the platform 17 extending to the left, in FIG. 13, of thefulcrum pin 102. This depresses the left edge of the platform, raisingthe main part of the platform toward a vertical position as illustratedin FIG. 15.

On pulling the other cord 121 the two cylinders are actuated in theopposite direction and both piston rods are pushed downward, causing thelift to go down and the platform to assume its horizontal attitude.

It is obvious that, in the linkage, FIGS. 13 - 15, the positions of thehydraulic cylinder 106 and the piston rod 108 could be interchanged, sothat the cylinder is secured to the angle piece 104 and the piston rodto the pivot 107, without departing from the general design and methodof operation of the lift.

What is claimed is:
 1. In an automobile having a van-type body,including body door openings provided with doors, a lift installedtherein comprising:a pair of linkage mechanisms secured to said body atone said door opening, each one of said pair of linkage mechanismsincluding: a suspension arm hingingly secured to said body at one endand depending therefrom in a substantially vertical direction; similarupper and lower pivot arms, each pivoted at one end to the lower end ofsaid suspension arm at points spaced by a selected distance; a verticalsupport connected by pivots at two points to the other ends of saidpivot arms, said two points being spaced by said selected distance,whereby said upper and lower pivot arms, and a portion of saidsuspension arm and of said vertical support constitute a pantograph; aguide arm pivoted at one end in one of said pivot arms and at the otherend in the van structure; said lift also comprising: a platform pivotedto and carried by said linkage mechanism; means for powering said lift;a cable connected to said platform and to said means for powering; and aminor linkage connected to one of said pivot arms and to said cablewhereby said platform can be raised and lowered and moved betweenhorizontal and vertical positions.
 2. A lift in accordance with claim 1in which said minor linkage comprises:an extension of one of said pivotarms and adjacent to said vertical support; a swing arm pivoted at oneend in said pivot arm extension; a cable attachment arm pivoted at oneend to the other end of said swing arm; and means securing the other endof said cable attachment arm to said cable.
 3. A lift in accordance withclaim 2 in which the link proportions in said linkage mechanism are asshown in the following table:

    ______________________________________                                        Link              Proportional                                                Designations      Number                                                      ______________________________________                                        a                 1                                                           b                 5.65                                                        c                 11.3                                                        d                 10                                                          e                 4.3                                                         f                 2.67                                                        g                 2.33                                                        h                 1.75                                                        ______________________________________                                    


4. In an automobile having a van-type body, including at least one bodydoor opening having two jambs and .[.providing.]. .Iadd.provided.Iaddend.with a door, a lift installed in said door opening comprising:apair of linkage mechanisms which are identical mirror images of eachother, each linkage mechanism being pivotally anchored to said body attwo places inside the outer surface of the body, one of said mechanismsbeing positioned on one side of the door opening and the other on theother side thereof, each said linkage mechanism including: a first linkcomprising a bar positioned approximately vertically; a pivot anchoringthe top end of said first link to said van body .[.above said dooropening adjacent one jamb thereof.].; a second link comprising a bar; apivot connection between one end of said second link and the bottom endof said first link; a third link comprising a bar; a pivot connection ofone end of said third link to said one jamb; a pivot connection of theother end of said third link to a point on said second link intermediatethe ends thereof, said point being at a distance f from said one end ofthe second link; a fourth link comprising a bar, said fourth linkconnecting the other end of said second link to said platform; said liftalso comprising: a platform secured to and carried by said pair oflinkage mechanisms; means connected to said fourth link for raising andlowering the link and said connected platform; means for powering saidlift; and means connected to said means for powering for raising andlowering said platform and for moving it between horizontal and verticalpositions.
 5. A lift in accordance with claim 4 in which:said means forpowering is electro-hydraulic; said means connected to said fourth linkfor raising and lowering comprises a hydraulic cylinder and piston rod,said piston rod being rigidly connected to said fourth link; and saidmeans connected to said means for powering for controlling the attitudeof the platform comprises a first rod having its lower end connected tothe rear of the platform and its upper end ending in a right-angledpiece surrounding said piston rod, whereby raising of the piston rodproduces downward thrust on the first rod in turn changing the platformto a vertical attitude.